Positivity rate dips in Mumbai even as Covid-19 cases surge
There has been a drop of four percentage points in positivity rate in Mumbai even as the number of Covid-19 cases have witnessed a surge over the past few weeks. Positivity rate reflects the proportion of people who test positive among those who are tested. It is a good indicator to assess the prevalence of the novel coronavirus infection in the community.
An analysis of data from the Brihanmumbai Municipal Corporation (BMC) Covid-19 dashboard reveals that between August 10 and August 24, 77,667 tests were conducted in the city and 14,529 people were diagnosed with Covid-19, which translates into a positivity rate of 18.70%. However, in the following two weeks, between August 25 and September 8, 20,580 Covid-19 cases were reported as 140,911 tests were conducted – a positivity rate of 14.60%.
“Till August 24, we were running daily average tests of around 5,500 in the city. But now, we have increased it by almost 50%. It has gone up to almost 9,500. On September 8, we tested around 13,000 people, which is a record,” said Suresh Kakani, additional commissioner, BMC, adding that if the number of infected people had increased, the positivity rate, too, should have risen. “But it has declined and that proves Mumbai’s Covid-19 case graph hasn’t shot up.”
The city’s overall positivity rate stands at 18.76% as on Wednesday, with 160,744 people having tested positive for Covid-19 from the 856,454 who were tested.
Health experts said despite increasing daily testing, Mumbai is far behind Bengaluru and Delhi in total number of tests. Bengaluru has tested around 1.1 million people, while in Delhi close to 2 million people have been tested. “The number of tests is equally proportionate to the number of positive cases. So, the more we test, the more cases will come out. This might create panic among people, but it will help to break the chain of infection. In fact, the civic body should have increased their testing much earlier, considering Mumbai is the most populated city,” said Anant Bhan, a public health expert.
Rapid antigen testing (RAT) has helped increase testing in Mumbai, as around 25% of the total tests conducted in the city are using RAT, which gives results in 30 minutes. For instance, on September 8, when 12,763 people were tested in Mumbai, 4,200 tests were conducted through RAT. “We are conducting close to 800 tests every day, that’s why we have the highest growth rate (1.61%). But we aren’t testing senior citizens above 50 years with RAT to rule out any chance of false negative reports,” said Bhagyashree Kapse, ward officer in R-Central (Borivli), which has recorded the third-highest number of cases.